# Angle sum of a Triangle for Class VII

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Category: Education

## Presentation Description

To verify the angle sum property & Exrerior angle property for a triangle by paper folding

## Presentation Transcript

### MATHEMATICS:

MATHEMATICS By MUKESH KUMAR, KV, No.1, Hindan Ghaziabad (UP) Delhi Region

### Different Figures:

Different Figures

### Definition:

Copyright © 2000 by Monica Yuskaitis Definition Triangle – a polygon with 3 angles and 3 straight sides.

### Sides of a triangle:

Sides of a triangle A B C

### Angles of a Triangle:

Angles of a Triangle Three Angles

### Today’s Topic------:

Today’s Topic------ Angle sum of a triangle

1A_Ch6( 7 )

### We take a cut out of a triangle:

We take a cut out of a triangle

### Cut all three angles of the triangles:

Cut all three angles of the triangles

### Three angles of the triangles--:

Three angles of the triangles--

### PowerPoint Presentation:

Sum of all angle = 180 0

### Exterior Angle of a triangle:

Exterior Angle of a triangle A C B > We can use previous knowledge of the properties of parallel lines >EXTEND the line AB to a point G G >DRAW line BE parallel to AC E

### Exterior Angle Property of a triangle:

Exterior Angle Property of a triangle A C B G E <ACB = <CBE Alternate Angles <CAB = <EBG Corresponding Angles <ACB + <CAB = <CBE + < EBG <ACB + <CAB = <CBG So, Exterior angle of a triangle is equal to the sum of its interior opposite angles

### THANKS A LOT…..:

THANKS A LOT….. MUKESH KUMAR , TGT (Maths) KV, No,1, AFS Hindan, Ghaziabad E-mail ID- mkprince2009@gmail.com & Blog Adress- www.mkumar4u.blogspot.com